Fall of humanity

All human beings, except for Jesus Christ, are sinful

Ro 3:23; Heb 4:15

See also Ge 6:5; Ge 6:11–12; Ps 14:1–3; Ps 51:5; Is 64:6–7; Jn 8:7; Ro 3:9–20; Ro 5:12–19; Eph 2:1–3

Every part of a person is affected by sin

The heart

Jeremiah 17:9 KJV 1900

The heart is deceitful above all things, and desperately wicked: who can know it?

See also Ge 6:5; Ge 8:21; 1 Sa 17:28; 2 Ch 12:14; Ps 66:18; Je 5:23; Mt 5:28; Mt 15:8; Mt 15:19

The body

Romans 6:6 KJV 1900

Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.

See also Ro 6:12–13; 1 Co 6:13; 1 Co 6:19–20

Human nature

Romans 8:5–8 KJV 1900

For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit. For to be carnally minded is death; but to be spiritually minded is life and peace. Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be. So then they that are in the flesh cannot please God.

See also Ro 7:5; 1 Co 5:5; Ga 5:19–21; Ga 6:8; Eph 2:3

Believers are warned not to fall from grace

Hebrews 3:12–14 KJV 1900

Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God. But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end;

See also Mt 24:12–13; 1 Co 15:2; Ga 5:4; Heb 4:11; Heb 12:15; 2 Pe 3:17; Re 2:4–5

God is able to keep believers from falling

Jude 24 KJV 1900

Now unto him that is able to keep you from falling, and to present you faultless before the presence of his glory with exceeding joy,

See also Job 33:14–18; Ro 16:25; Eph 6:13; 1 Jn 5:18